Forced draft unit for floor furnaces



Patented A rriz, 193s PATENT OFFICE roman DRAFT UNIT FOR. FLOOR FURNACESRobert E. Newman, Los Angeles, Calif; assignor to The Coleman Lamp andStove Company, Wichlta Kans a corporation of Kansas Q I 1 v"ApplicationApril 11, I936, Serial No. 73,912

6 Claims.

This invention relates to heaters and particularly to that class ofheater for use in dwellings or the like which have no cellar or basementand are designed for suspension from the floor joists 5 so that theyarecommonly known asfloor furnaces. The invention has todo moreparticularly with a general type of floor furnace similar to thatdisclosed in the patent to R; E. Fraser of March 20, 1934, Number1,952,009 in which air to 1;) be heated 'is normally circulated bythermic 'action downwardly within anouter casing and upwardly through avertical heating flue. I have found that in many installations theairdoesnot circulate with suflicient velocity and volume'to l5 obtainmaximum heat recovery from the combusted fuel and that it is desirableto providemechanical means for increasing the air circulation throughthe furnace.

Q My invention therefore contemplates a novel 20 unitary forced draftunit, for impelling air up {through the heating flue, the unit beingso'designed and associated with the. heating flue that it may be easilyremovablefor inspection and repairs.- The novelty of the inventionwillbe 25 apparent by reference'togthefollowing descrip- H tion inconnection withithe accompanying drawinginwhich: I

Fig. 1 is a fragmentary perspectiveviewof a heater to which my inventionis applied.

50 Fig. 2 is a detailisection through the lower portion of theheatercasing and air heating flue, par- I ticularly illustrating;installation .of the forced" centric alignment with the axis of the airheatdraft unit.

I designates the heater casing which is pro-v 35 vided with opposedvertical walls,2-2' and 33' and a bottom 4. The casing l is suspendinglyconnected with the floor 5 by any suitable means and. it is provided atits top with a removable register or grill 6 covering the open topthereof 4 in substantially the plane of the floor. A heater unit 1 isdisposed within the casing I and it is provided at its bottom with aburner 8 supplied from any suitable source to heatthe air surroundingthe heater unit I, the unit! having an outlet 45 9 at. its topdischarging into a down draft flue Ill and out through a pipe ll. Withinthe down draft flue i0 is an air heating flue [2 having its lower endspaced from thebottom 4 to provide communication with the space l3between the 50 casing l and a jacket N that encloses the heater casingI. The cold air to be heated gravitates from the room through the grill6 and moves support the unit and to provide a tight seal aboutdownwardly through the spacei3 and under the lower edge. of the jacket Hfor upward passage in heat contacting relation with the heater unit (on.ice-11o) I. The air upon contacting the heater unit becomesheated andrises upwardly through the grill for return to the room. Some of thecool air moves upwardly through the air heating flue l2 and is heatedsufllciently therein so that it 5 moves with a velocity to direct an updraft through the furnace to maintain circulation of the air. Thisgeneral construction of the heater and its operation is all old and wellknown but many times it is desirable to increase the up draft throughthe flue H by providing a forced draft unit including a motor driven fanthat is supported below the lower end of the flue l2 to draw the airdownwardly through the space l3 and 15 impel it upwardly through theheating flue l2, thereby positively increasing the velocity and volumeflow of air through the furnace. In mounting the unit I find itdesirable that the motor be located exteriorly of the casing I so thatit is out of the heat influencing zone'of the heater and removed fromthe path of the circulated air. The motor is thus not only protectedfrom the dust carried by the air but also from the dust and dirtdropping through the grill into the heater casing. Another advantage isthat the motor does not overheat and the lubrication is more effectivesince the motor is located within the relatively cold air surroundingthe casing of the heater. the forced draft unit by the bottom 4 of thecas: ing l, with the axis of the motor located in coning flue. Owing tothe fact that the motor is supported exteriorly of the casing I, and dueto' the'fact that'the exterior of the casing is not accessible afterinstallation of the furnace, provision is made'for servicing the forceddraft unit by withdrawing it through the up draft flue. When thuswithdrawn theunit is readily inspect- 40 ed and; lubricated withoutremoval of the heater casing- In carrying out my invention I provide anopening I5 in the bottom 4 of the casing l and locateddirectly below theflue l2 to pass the motor it of the forced draft unit. The electricmotor It carries a shaft l1 on the end of which is an impeller or fan I8to force the air up through the flue l2. The upper end of the motor alsocarries a plate l9 of sufficient diameter to overlap the peripheral edgeof the opening l5 so that when the motor is in place'the periphery ofthe plate rests upon the bottom of the casing I to the opening. In orderto guidingly support the Provision is made, therefore, to carry 30fingers 20 which are of sufficient length to projectingly engage thelower end of the flue I2 when the plate I9 is seated on the bottom ofthe casing I, as clearly shown in the drawing. When the forceddraft unitis thus supported the motor extends below the bottom of the casing I andit is provided with terminals 2| and 22 to which the conductors 23 and24 are attached. The conductors 23 and 24 are flexible and havesuificient slack to permit removal of the forced draft unit through theopen top 25 of the flue l2. In order to facilitate removal of the unitthe top of the shaft I1 is provided with an eye or loop 26 so that ahooked rod (not shown) may be inserted through the open top 25 in theflue I2 to permit the hook to engage the eye or loop 26 so that thecomplete forced draft unit may be lifted up through the flue l2 forinspection and repairs. It is to be understood that the forced draftunit is installed and the electrical connections are made thereto priorto placement of the heater casing.

When it becomes necessary to remove the forced draft unit as when makingan inspection or repairing and lubricating the motor, the grill 6 isremoved. The hooked rod above mentioned is then lowered through the openend 25 of the flue l2 to engage the hooked end thereof with the eye orloop 26. The rod is then withdrawn, bringing out the forced draft unitincluding the conductors 23 and 24, the unit being guided upwardlywithin the flue by the relatively close engagement of the fingers 20.After the unit has been serviced it is readily lowered by means of thehooked rod into the open end of the flue l2 and guided by the fingers 20so that the motor l6 passes through the opening l5. When the plate l9has been seated onthe bottom of the casing the hooked rod is disengagedfrom the eye or loop 26 and the rod withdrawn, leaving the unit incentered relation with the lower end of the flue due to the engagementof the terminal ends of the fingers 20. The grill 6 is then replaced tocontinue the operation of the furnace. It is thus obvious. that thisarrangement makes for convenience in assembly and for inspection andrepairs of the forced draft unit and renders it easily accessible.

What I claim is:

1'. 'In combination with a floor furnace including a heater unit, aburner in the heater unit, an air heating flue extending through theheater unit, a casing for the heater unit having an open top normallycovered by a grill and a bottom provided with an opening aligning withthe air heating flue, a forced draft unit for circulating air downwardlywithin the casing for discharge through said grill by the way of saidflue including a motor located in said opening and extending exteriorlyof the casing, means on the motor for closing said opening and forsuspendingly supporting the motor from the bottom of the casing, and afan carried by the motor for forcibly discharging the circulated airthrough said flue.

2. In combination with a floor furnace including a heater unit, a burnerin the heater unit, an air heating flue extending through the heaterunit, a casing for the heater unit having an open top normally coveredby a grill and a bottom provided with an opening aligning with the airheating flue, a forced draft unit for circulating air from said open topand downwardly within the casing for discharge through the open top bythe way of said flue including a motor located in said opening andextending exteriorly of the casing, means on the motor for closing saidopening and for suspendingly supporting the motor from the bottom of thecasing, a fan carried by the motor, and means on said supporting meansfor centering said forced draft unit relatively to the air heating flue.

3. In combination with a floor furnace including a heater unit, a burnerin the heater unit, an air heating flue extending through the heaterunit, a casing for the heater unit having an open top normally coveredby a grill and a bottom provided with an opening aligning with the airheating flue, a forced draft unit for effecting circulation of airdownwardly within the outer casing for discharge of the air through thegrill by the way of said flue including a motor located in said openingand extending exteriorly of the casing, means on the motor for closingsaid opening and for suspendingly supporting the motor, a fan carried bythe motor, and means connected with said forced draft unit and adaptedto be engaged by a hooked rod for removal of said forced draft unitupwardly through said flue and through the open top of the casing.

4. In combination with a floor furnace including a heater unit, a burnerin the heater unit, an air heating flue extending through the heaterunit, a casing for said unit having an open top normally covered by agrill and a bottom provided with an opening aligning with the airheating flue a forced draft unit for circulating air downwardly withinthe outercasing for discharge through said grill by the way of said flueincluding a motor located in said opening and extending exteriorly ofthe casing, means on the motor for closing said opening and forsuspendingly supporting the motor from the bottom of the casing, a fancarried by the motor, means on said supporting means for centering saidforced draft unit relatively to the air heating flue, and meansconnected with said unit and adapted to be engaged by a hooked rod forremoval of said forced draft unit upwardly through said flue and throughthe open top of the casing when the grill is removed.

5. In combination with a floor furnace including a heater unit, a burnerin the heater unit, an air heating flue extending through the heaterunit, a casing for the heater unit having an open top normally coveredby a grill and a bottom provided with an opening aligning with the airheating flue, a forced draft unit for circulating air downwardly withinthe casing for discharge through the grill by way of said air heatingflue including a motor located in said opening and projecting from theexterior of the casing, means on the motor for closing said opening andfor suspendingly supporting the motor from the bottom of the casing, afan carried by the motor, and guide means on said supporting meanshaving upwardly extending fingers guidingly engaging the inner surfaceof the air heating flue for centering said forced draft unit relativelyto the flue.

6. In combination with a floor furnace including a heater unit, a burnerin the heater unit, an air heating flue extending through the heaterunit, a casing for the heater unit having an open topnormally covered bya grill and a bottom provided with an opening aligning with the airheating flue, a forced draft unit for circulating air downwardly withinthe outer casing for discharge through the grill by the way of said airheating flue including a motor projecting through said said forced draftunit relatively to the flue, and means connected with said forced draftunit and adapted to be engaged by an elevating tool for moving saidforced draft unit through the up draft flue to and from support by saidbottom.

ROBERT E. NEWMAN.

